Improving the efficiency of heat exchanger using spray evaporative cooling

在水冷式空气处理器中，冷却和加热供应给建筑物的空气，冷却盘管通常在进入空气的露点温度以下运行，以最大限度地提高合理的冷却能力以及提供除湿。在冷却盘管翅片上形成的冷凝水通常被收集在排水系统中，并使用倾斜管道或冷凝泵除去。由于冷凝液的温度接近盘管翅片的温度，这种情况代表了一个未开发的额外冷却机会。这对于Price industries Ltd（一家总部位于马尼托巴省温尼伯的采暖、通风和空调（HVAC）公司）生产的热交换器装置来说是典型的。该公司的目标是在喷雾/蒸发冷却应用中重新使用冷冷凝水，在热空气到达冷却盘管进行额外冷却之前对其进行预冷却。预计这种方法将提高空气处理机组的冷却效率。然而，这一概念的实施需要对喷雾流量的相关变量（例如，气流速度，水流速率，液滴形成（喷雾）和分布等）进行全面的优化研究，以便最大限度地利用冷凝水实现预冷量。量化蒸发预冷对冷却盘管潜在容量的影响将是本研究/项目的另一个有益组成部分。本研究的目的是开发一种有效的喷雾冷却策略，以最大限度地提高暖通空调预冷系统的液体/空气传热。这些装置效率的提高将有助于增加和加强Price Industries Ltd的市场份额，从而提高加拿大暖通空调行业的市场份额。

In a water cooled air handler, which cools and heats the air supplied to a building, the cooling coil typicallyruns below the dew-point temperature of the incoming air in order to maximize sensible cooling capacity aswell as to provide dehumidification. The condensate that forms on the fins of the cooling coil is typicallycollected in a drainage system and is removed using sloped piping or a condensate pump. Since the temperatureof the condensate is close to the temperature of the coil fins, this scenario represents an untapped opportunityfor additional cooling. This is typical for heat exchanger units manufactured by Price industries Ltd, a Heating,Ventilation and Air-Conditioning (HVAC) company headquartered in Winnipeg, Manitoba. The objective ofthe company is to reuse the cold condensate in spray/evaporative cooling application to pre-cool the warm airbefore it reaches the cooling coil for additional cooling.It is expected that this approach would increase the cooling efficiency of the air handling unit. However, theimplementation of this concept requires a comprehensive optimization study with respect to the pertinentvariables of the spray flow (e.g., airflow velocity, water flow rate, droplets formation (spray) and distribution,etc) in order to maximize the amount of pre-cooling that can be achieved with the condensate. Quantifying theeffect of this evaporative pre-cooling on the latent capacity of the cooling coil would be another beneficialcomponent of this study/project.The objective of the proposed research is to develop an efficient spray cooling strategy to maximize liquid/airheat transfer of HVAC precooling systems. The resulting improvement in the efficiency of these units will helpincrease and strengthen the market share of Price Industries Ltd and consequently the Canadian HVACindustry.